There are different "first kisses". There is the stamp-like one with just a quick touch of two compressed lips*, mostly happened during our childhood. If I remember well, I was like ten. The after-reaction? Two fast steps backward and the lip whipping, made simultaneously, to finish with a bit blushy smile.

But I guess we all think that the first one, the real one is composed by four** basic ingredients: mouth, tongue, love and passion. I guess I do not need to explain the technique of how to...the base is always the same + some personalization by each of us. This one happened quite late...the last day of the second grade during the High school. The combination of Love and passion makes even the worst thing, the best ones.

And there are first kisses, that they become always first with a new person...a first kiss with that person. On a first date or on a day you meet for the first time the person***, like in this video... of 20 strangers sharing a first kiss. It was made by a filmmaker Tatia PIlieva as part of L.A. label Wren’s fall ad campaign.

a similar shape of lips you get after you squeeze with them a lemon
** almost
*** party, a "hormone" crush,...